a. Field of the Invention
The invention pertains to the field of tampers for corrosive battery mixes and alloys possessing excellent corrosion.
B. Description of the Prior Art
In the dry battery industry, it is a common practice to tamp a powder mixture of manganese dioxide, graphite, ammonium chloride, zinc chloride, etc., as the battery mix into various shapes. However, the mixture is strongly corrosive, therefore ordinary metals cannot be used for this purpose.
In the past, ceramics were chiefly used for the purpose, however they are easily broken by impacts and special care was required for their handling.
Then Stellite No. 4 alloy was developed as an alloy for overcoming the corrosion and wear problems and has been used as tamping devices, such as, powder boxes, various dry battery tamping molds, holders, sleeves and extrusion dies for small batteries. However, Stellite No. 4 is available only in the cast form and it is impossible to obtain a uniform composition due to segregation and the variation in the quality on a lot by lot basis is large. Further, its length of service is, at best, only one and a half months.